The present invention relates to a magnetic resonance imaging (hereinbelow abbreviated to MRI) apparatus, in which nuclear magnetic resonance (hereinbelow abbreviated to NMR) signals coming from hydrogen, phosphor, etc. in a subject are measured to provide an image density distribution of nuclei, relaxation time distribution, etc., as well as an RF probe for MRI suitable for use for a signal detecting section in an MRI apparatus.
In an MRI apparatus, signals coming from an interested part of a subject (e.g. human being) are detected by means of a resonance type high frequency coil. As a method for increasing sensitivity of the coil, there is known a method, by which a plurality of coils are juxtaposed and signals obtained by the different coils are joined to synthesize an NMR signal. The principle of this method is described in JP-A-Hei 2-500175 or Magnetic Resonance in Medicine, Vol. 16, pp. 192-225 (1990).
By the prior art techniques, if outputs of a probe are simply joined to detect a synthesized signal, since signal to noise ratio (S/N ratio) is not increased, it is necessary to detect the plurality of outputs of the probe separately in order to increase the S/N ratio. For this reason electromagnetic coupling between different coils should be removed to reduce correlation of noise between different coils. However, when coupling between different coils is strong, there is no means for removing stably electromagnetic coupling between different coils. Therefore there was a problem that it was not possible to reduce satisfactorily the correlation of noise between different coils.